1. Field of the Invention
This invention relates to the shift mechanism for a manual transmission of the type used in an automotive vehicle.
2. Description of the Prior Art
A positioning device for a gear-shift shaft in a transmission of a motor vehicle is described in German Patentschrift DE 36 02 157.
This positioning device, which holds several axial positions of the gear-shift shaft of a manual transmission, the shaft is held rotatably and axially displaceably in a bearing bore formed in the transmission housing to perform gear-shifting, selecting and engaging movements. The shaft is axially positioned by means of a depression in the shaft and by engagement of a spring-loaded ball held axially in the housing with the depression.
This positioning device has the disadvantage that the depressions are constructed directly on the shaft and that the detent ball has its axial location determined by a sleeve held against displacement on the housing. Due to accumulation of normal production tolerances, the axial location of the assembled shaft relative to the location of the sleeve leads to considerable deviation in the position established by the positioning device from the desired actual shift position of the gear-shift shaft.
German Offenlegungsschrift DE-PS 36 03 609, describes a device for positioning a gear-shift shaft of a transmission, in which depressions for locating the shaft radially are formed on a component connected to the shaft and in which catch bolts are constructed in the form of balls held in a part pressed by a spring axially onto a component connected to the shaft. That component is held in the housing against rotation.
The radial position of the gear-shift shaft is established by the position of depressions in the component connected to the shaft. Rotation of the shaft to its neutral gear-shift plane results due to the inclination of the connecting faces between the depressions as the balls move out of the depressions.
The positioning device of the '609 document has the disadvantage that additional components requiring considerable space have to be located on the shaft. Also, the angular location of the shaft, but not its axial position, is achieved by the device.